3,133 research outputs found
Anabasis articulata (Forssk.) Moq. food aqueous extract triggers oxidative stress-induced senescence and reduces metastatic power in MDA-MB-231 cells
Ancient ethnobotanical practices handed down through traditional knowledge are still commonly employed to treat various pathologies, although the scientific reasons underlying their biological effects have not been clarified yet. In this contribution, the potential antitumoral activity of the aqueous extract from A. articulata (AAE) was investigated to validate the hypothesis of the Algerian folk medicine which would suggest this plant derivative as a functional food for treating breast cancer. A. articulata phytocomplex, isolated by maceration following exactly the African recipe, has been already characterized by our research group in previous works. Thus, the antiproliferative function of AAE against MDA-MB-231, a highly aggressive human breast adenocarcinoma cell line, was evaluated. Slowing down of cell growth, absence of cytotoxicity and DNA fragmentation, and cell cycle arrest at the G2/M phase were observed after treatment with AAE at different doses (0.3–6 mg of dried plant material equivalent per mL of culture medium) for 24 and 48 h. Wound and transwell assays proved that AAE possessed both antimigration and antiinvasive capacities, evidence also supported by molecular analyses focused on Metalloproteases (MMP-2 and MMP-9), Vimentin and ανβ3-Integrin. These results, together with the demonstration of the activation of p53/p21WAF1/Cip1/p27Kip1 pathway and the increase of oxygen reactive species levels, suggested that AAE triggered a senescence process. The final confirmation was obtained by a specific kit staining senescent cells. All our data would explain the efficacy of the Algerian medicinal remedy based on the intake of the investigated functional plant food and would highlight the basics for developing novel natural pharmacological products based on AAE and showing preventive and therapeutic antineoplastic potentialities against highly aggressive breast cancers
The Certification of ATLAS Thin Gap Chambers Produced in Israel and China
Thin gap chambers (TGCs) are used for the muon trigger system in the forward
region of the LHC experiment ATLAS. A TGC consists of a plane of closely spaced
wires maintained at positive high voltage, sandwiched between resistive
grounded cathode planes with an anode wire to cathode plane gap distance
smaller than the wire-to-wire spacing. The TGCs are expected to provide a
trigger signal within 25 ns of the bunch spacing of the LHC accelerator, with
an efficiency exceeding 95%, while exposed to an effective photon and neutron
background ranging from 30 to 500 Hz/cm2. About 2,500 out of the 3,600 ATLAS
TGCs are being produced at the Weizmann institute in Israel, and in Shandong
University in China. Once installed in the ATLAS detector the TGCs will be
inaccessible. A vigorous production quality control program is therefore
implemented at the production sites. Furthermore, after chamber completion, a
thorough program of quality assurance is implemented to ensure the efficient
performance of the chambers during more than ten years of operation in the LHC
high rate environment. This program consists of a detailed mapping of the
detectors response using cosmic rays, as well as checking the chambers behavior
using a high rate radiation source. An aging test performed on five chambers in
a serial gas connection is presented. Finally the results of the chambers
certification tests performed at CERN before the installation in ATLAS are
described.Comment: Presented at 2004 IEEE Nuclear Science Symposium 2004, Rome, Oct 200
The interrelatedness of cognitive abilities in very preterm and full‐term born children at 5.5 years of age : a psychometric network analysis approach
Background
Very preterm (VP) birth is associated with a considerable risk for cognitive impairment, putting children at a disadvantage in academic and everyday life. Despite lower cognitive ability on the group level, there are large individual differences among VP born children. Contemporary theories define intelligence as a network of reciprocally connected cognitive abilities. Therefore, intelligence was studied as a network of interrelated abilities to provide insight into interindividual differences. We described and compared the network of cognitive abilities, including strength of interrelations between and the relative importance of abilities, of VP and full-term (FT) born children and VP children with below-average and average-high intelligence at 5.5 years.
Methods
A total of 2,253 VP children from the EPIPAGE-2 cohort and 578 FT controls who participated in the 5.5-year-follow-up were eligible for inclusion. The WPPSI-IV was used to measure verbal comprehension, visuospatial abilities, fluid reasoning, working memory, and processing speed. Psychometric network analysis was applied to analyse the data.
Results
Cognitive abilities were densely and positively interconnected in all networks, but the strength of connections differed between networks. The cognitive network of VP children was more strongly interconnected than that of FT children. Furthermore, VP children with below average IQ had a more strongly connected network than VP children with average-high IQ. Contrary to our expectations, working memory had the least central role in all networks.
Conclusions
In line with the ability differentiation hypothesis, children with higher levels of cognitive ability had a less interconnected and more specialised cognitive structure. Composite intelligence scores may therefore mask domain-specific deficits, particularly in children at risk for cognitive impairments (e.g., VP born children), even when general intelligence is unimpaired. In children with strongly and densely connected networks, domain-specific deficits may have a larger overall impact, resulting in lower intelligence levels
Measurement of shower development and its Moli\`ere radius with a four-plane LumiCal test set-up
A prototype of a luminometer, designed for a future e+e- collider detector,
and consisting at present of a four-plane module, was tested in the CERN PS
accelerator T9 beam. The objective of this beam test was to demonstrate a
multi-plane tungsten/silicon operation, to study the development of the
electromagnetic shower and to compare it with MC simulations. The Moli\`ere
radius has been determined to be 24.0 +/- 0.6 (stat.) +/- 1.5 (syst.) mm using
a parametrization of the shower shape. Very good agreement was found between
data and a detailed Geant4 simulation.Comment: Paper published in Eur. Phys. J., includes 25 figures and 3 Table
Performance of fully instrumented detector planes of the forward calorimeter of a Linear Collider detector
Detector-plane prototypes of the very forward calorimetry of a future
detector at an e+e- collider have been built and their performance was measured
in an electron beam. The detector plane comprises silicon or GaAs pad sensors,
dedicated front-end and ADC ASICs, and an FPGA for data concentration.
Measurements of the signal-to-noise ratio and the response as a function of the
position of the sensor are presented. A deconvolution method is successfully
applied, and a comparison of the measured shower shape as a function of the
absorber depth with a Monte-Carlo simulation is given.Comment: 25 pages, 32 figures, revised version following comments from
referee
Background Light in Potential Sites for the ANTARES Undersea Neutrino Telescope
The ANTARES collaboration has performed a series of {\em in situ}
measurements to study the background light for a planned undersea neutrino
telescope. Such background can be caused by K decays or by biological
activity. We report on measurements at two sites in the Mediterranean Sea at
depths of 2400~m and 2700~m, respectively. Three photomultiplier tubes were
used to measure single counting rates and coincidence rates for pairs of tubes
at various distances. The background rate is seen to consist of three
components: a constant rate due to K decays, a continuum rate that
varies on a time scale of several hours simultaneously over distances up to at
least 40~m, and random bursts a few seconds long that are only correlated in
time over distances of the order of a meter. A trigger requiring coincidences
between nearby photomultiplier tubes should reduce the trigger rate for a
neutrino telescope to a manageable level with only a small loss in efficiency.Comment: 18 pages, 8 figures, accepted for publication in Astroparticle
Physic
Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC
The uncertainty on the calorimeter energy response to jets of particles is
derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the
calorimeter response to single isolated charged hadrons is measured and
compared to the Monte Carlo simulation using proton-proton collisions at
centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009
and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter
response to specific types of particles (positively and negatively charged
pions, protons, and anti-protons) is measured and compared to the Monte Carlo
predictions. Finally, the jet energy scale uncertainty is determined by
propagating the response uncertainty for single charged and neutral particles
to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3%
for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table,
submitted to European Physical Journal
Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC
Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson
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